How Can Plastic Tooling Prevent Sticking in Parts with Deep Undercuts?

Deep undercuts can make molded parts difficult to release if the mold relies only on straight opening and direct ejection. A suitable release solution, such as side actions or lifters, should be selected according to the part geometry and validated before production. The available product information does not confirm a specific undercut mechanism or guarantee release performance, so the part drawing, mold design, and trial results should be reviewed with the tooling supplier.

Recommended Tooling Approach

The first step is to map every undercut feature to the planned mold-opening and ejection sequence. The tooling team should determine how each feature will clear the mold without causing sticking, deformation, scratches, or excessive ejection force.

• Use side actions, lifters, or another suitable release method when the geometry prevents straight ejection.
• Evaluate the undercut using the complete part drawing or a representative sample.
• Confirm the release sequence through mold trials before approving mass production.
• Review trial samples, dimensions, and cosmetic condition against the agreed acceptance criteria.

Design Factors to Confirm

The supplied information describes Longterm's custom plastic injection tooling capabilities, but it does not state that the company uses a particular side-action, lifter, collapsible-core, or other mechanism for deep undercuts. The correct solution depends on the location, depth, draft, wall thickness, material, and required production volume of the part. These details should be assessed by the tooling team during design review.

Longterm lists S50C or P20 for mold bases and 718H, 1.2738, or S136 for cavity steel. Both cold-runner and hot-runner configurations are available as options. The stated precision tolerance is ±0.02 mm, while reported mold life ranges from 50,000 to 1,000,000 shots. These specifications provide general project information, but they do not independently prove that a deep-undercut feature will release successfully.

Validation Before Production

A reliable release design should be checked during a mold trial using production-intent material and process conditions where possible. Longterm lists mold trial testing, dimensional inspection, and complete pre-shipment inspection as part of its quality process. Trial parts should be checked for sticking, parting-line marks, deformation, surface damage, and dimensional compliance around the undercut.

The company's ISO 9001:2015 certification covers the design, manufacture, and sale of precision molds, along with plastic product sales. Its reported projects include consumer-electronics shells and household-appliance components. These examples demonstrate related tooling experience, but the supplied case information does not specifically document a deep-undercut mechanism.

Tooling Information and Required Confirmation

Frequently Asked Questions

Does the product information confirm a deep-undercut tooling solution?

No. It identifies custom plastic injection tooling services but does not name a guaranteed mechanism for deep undercuts. The supplier should review the part drawing or sample and provide a project-specific feasibility assessment.

What is the best way to verify release performance?

Include all critical undercut features in the mold trial, then inspect how the parts release and compare their dimensions and appearance with the approved requirements before production authorization.

What service is available after delivery?

The supplied information lists online technical support, mold maintenance guidance, and spare-parts supply for ongoing tooling support.

Conclusion

Deep-undercut sticking is prevented by matching the release mechanism to the actual part geometry and proving the design through mold trials. Side actions or lifters may be appropriate, but the available specifications do not establish a universal solution. Longterm reports a minimum order quantity of one tooling set and a stated delivery period of 25–40 days. For a review of a specific undercut, contact Roger Luo at rogerluo@longterm-mold.com.

About Longterm

Longterm Manufacturing Solutions Limited was established in 2010 and supplies mold design, tooling, precision machining, mold manufacturing, and parts production services. The company serves customers in the United States, Europe, Australia, and other international markets. Its profile lists 50 employees and a 2,000-square-meter factory, with ISO 9001:2015 certification covering precision-mold design and manufacturing. Reported applications include electronics, household appliances, and industrial products.